Recombination component of the current is quite difficult to calculate because we need to know the mean electron and hole recombination times in the SCL.

A、Genetic recombination of alleles is associated with physical exchange between chromosomes.

B、Genes are located on chromosomes and the map distance between them could often be measured by the number of nucleotides in the DNA.

C、Determining map distances in humans could be done by using pedigrees and calculating lod scores.

D、Association studies allow genes that have no obvious phenotype to be accurately mapped.

E、Crossing over does not occur in male Drosophila, so there is no genetic recombination.

Harry has been unable to calculate his business' profit or loss for the year ended 31 December 20X8 as fire destroyed most of his accounting records. He has, however, been able to provide the following information. Net assets at 31 December 20X7 were $23,000 and $32,500 at 31 December 20X8. He introduced capital during the year of $4,000 cash. He took cash drawings of $2,500 and goods with a selling price of $800; the cost of the goods was $750. What was Harry's profit for the year ended 31 December 20X8?

A、$8,750 profit

B、$2,250 profit

C、$8,800 profit

D、$2200 profit

The material for students to read is ______ difficult because it is abstracted from the foreign magazine.

A．fairly too

B．rather too

C．quite too

D．pretty too

Which of the following is necessary in a disaster preparedness plan?

A．Food, water, a telephone with extra batteries.

B．Food, water, a flashlight with extra batteries.

C．Food, a telephone with extra batteries and a meeting place in case of evacuation.

D．Water, a telephone with extra batteries and a meeting place in case of evacuation.